tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

util-lib: move a number of fs operations into fs-util.[ch]

util-lib: split our string related calls from util.[ch] into its own file string-util.[ch] There are more than enough calls doing string manipulations to deserve its own files, hence do something about it. This patch also sorts the #include blocks of all files that needed to be updated, according to the sorting suggestions from CODING_STYLE. Since pretty much every file needs our string manipulation functions this effectively means that most files have sorted #include blocks now. Also touches a few unrelated include files.

remove unused includes This patch removes includes that are not used. The removals were found with include-what-you-use which checks if any of the symbols from a header is in use.

util: rework strappenda(), and rename it strjoina() After all it is now much more like strjoin() than strappend(). At the same time, add support for NULL sentinels, even if they are normally not necessary.

system-update-generator: accept a dangling symlink The offline update mechanism is explicitly designed to work with a separate /var. systemd-update-generator is supposed to run early, before filesystems are mounted, so it cannot check if the /system-update symlink actually points to anything. The update is run *after* filesystems are mounted, so it should be able to access the target of the symlink without trouble. https://bugzilla.redhat.com/show_bug.cgi?id=1178978

treewide: another round of simplifications Using the same scripts as in f647962d64e "treewide: yet more log_*_errno + return simplifications".

treewide: use log_*_errno whenever %m is in the format string If the format string contains %m, clearly errno must have a meaningful value, so we might as well use log_*_errno to have ERRNO= logged. Using: find . -name '*.[ch]' | xargs sed -r -i -e \ 's/log_(debug|info|notice|warning|error|emergency)\((".*%m.*")/log_\1_errno(errno, \2/' Plus some whitespace, linewrap, and indent adjustments.

system-update-generator: modernizations

Standarize on one spelling of symlink error message It's polite to print the name of the link that wasn't created, and it makes little sense to print the target.

log.h: new log_oom() -> int -ENOMEM, use it also a number of minor fixups and bug fixes: spelling, oom errors that didn't print errors, not properly forwarding error codes, few more consistency issues, et cetera

readahead: use Conflicts= instead of masking to get rid of readahead units

readahead: disable collect/replay during system updates

manager: rework generator logic Previously generated units were always placed at the end of the search path. With this change there will be three unit dirs instead of one, to place generated entries at the beginning, in the middle and at the end of the search path: beginning: for units that need to override all configuration, regardless of user or vendor. Example use: system-update-generator uses this to temporarily redirect default.target. middle: for units that need to override vendor configuration, but not vendor configuration. Example use: /etc/fstab should override vendor supplied configuration (think /tmp), but should not override native user configuration. end: does not override anything but is available as well. Possible usage might be to convert D-Bus bus service files to native units but allowing vendor supplied native units to win.

log: make sure generators never log into the journal to avoid activation deadlocks This makes all generators log to kmsg by default.

mount: drop unused function

system-update: add system update generator http://freedesktop.org/wiki/Software/systemd/SystemUpdates